The delta Covid variant is one of the most infectious respiratory diseases ever seen by scientists, the director of the Centers for Disease Control and Prevention said Thursday.
The variant is highly contagious, largely because people infected with the delta strain can carry up to 1,000 times more virus in their nasal passages than those infected with the original strain, according to new data.
The delta variant has spread quickly through the U.S., accounting for more than 83% of sequenced cases in the U.S.
counties with low vaccination rates, while counties with high vaccination rates are seeing lower rates of new cases.
Three states, Florida, Texas and Missouri, with low vaccination rates accounted for 40% of all new cases nationwide, White House Covid czar Jeff Zients said.